Various types of networks involving switches are in common use such as public and private telephone networks, local area networks (LAN) and wide area networks (WAN). LAN and WAN networks are largely digital and generally use asynchronous transfer mode (ATM) signals, whereas telephone networks typically use analogue or synchronous digital signals (SONET).
Broadband telecommunications networks involve networks containing hardware switches of various types, and for a given type, of different manufacturers. Such a network could contain frame relay, ATM and/or baseband analogue switches. For example, the switches in one city could be primarily analogue switches while those in another city could contain ATM switches or a mixture of ATM and analogue switches.
In general, switches of one manufacturer are controlled using different protocols from those of other manufacturers. In order to set up a call that would use various switches, a switch controller would have to be created for each instance of switch hardware encountered. In addition, each controller node would have to know the protocol of each switch at every location. Consequently, if a given switch were changed to a different hardware type or manufacturer, a new switch controller for controlling that switch would have to be created and the interaction between the switch controller and the controller node would have to be modified. Obviously, such a system is complex and inefficient.
As a result of these difficulties, there is a need for an adaptive, modifiable, extensible and reusable solution to controlling and implementing a network switching system through the switch controllers.
Addressing the need for a switch controller framework that can extend to different switch types and different manufacturers is not a trivial task. Typically, each switch type has a specific control protocol and message passing protocol and these protocols may vary with manufacturers within the same switch type. For example, an analogue switch is typically controlled on a connection-by-connection basis where a single command performs a single connection. On the other hand, for an ATM switch, several connections may be grouped into a single logical unit and a single command may be all that is necessary to make a broadcast connection such that one port is connected to many other ports.
It is, therefore, an object of this invention to provide a method for grouping related connections into logical units.
It is a further object of this invention to provide a switch controller mechanism such that different kinds of switches can be supported and different switch controllers can be derived from a single code base.